LED Speedometer is a speed meter app with colourful LED screen.
And It is a digital speedgauge app which uses GPS system.
So you will need an active GPS connection for the app work.
It shows you speed (velocity). Stay safe by driving using the speed limit alert function.
You can use this app with bike smartphone holder and anything else, especially HUD with your car.
HUD means Head Up Display.

Kilometers(km/h), Miles(mph) and Nautical mile(kts,knots,kn) are supported in this app.
Landscape mode and Portrait mode are supported.

NOTE: Due to phone GPS limitation, It may not work well in cloudy weather or indoor places.
And I don't guarantee that it shows accurate data because of GPS errors.